Pyracantha needs to be tied in to wires
Plants can be trained, by means of tying-in and/or judicious pruning, to take a desired shape or to fill an allotted space. Climbing plants and wall shrubs such as pyracantha, cotoneaster and winter jasmine usually need to be trained, but a tree or shrub may also need to have its shape adjusted by tying in or by pruning.
Where possible, tie in young shoots to the required position. On walls, use wires about 25 centimetres apart, fixed to brass screws or masonry nails driven into the wall. Wooden trellis makes an attractive support for climbing shrubs. Screw the trellis to wooden battens fixed with screws to the wall. If necessary, this allows the trellis to be easily taken down.
Use soft jute string, not plastic string, to tie in plants. The soft string breaks down and rots in a year or so and there is no danger of constricting the branches. Tie in the new shoots as they grow. If young shoots cannot be tied in to a suitable position, or if there are too many suitable shoots, prune out the surplus where they arise, during the summer.